The present invention relates to a single lever mixing valve and more particularly to a single lever mixing valve having an improved operability.
The Single lever mixing valve is used a lot in a kitchen, a washing stand, and the like owing to its convenience.
The Single lever mixing valve is described below with reference to FIG. 13 showing a cartridge of the Single lever mixing valve.
A handle lever 8 is directly connected to a disk actuating stem 2 to transmit the motion of the handle lever 8 to a movable disk 4.
Cold and hot water enter the Single lever mixing valve from inlets port 6, pass through holes of a fixed disk 5, and are discharged from a outlet port 7 through a path shown with an arrow E.
A lever holder 1 is assembled inside the cartridge. The disk actuating stem 2 transmits a linear motion of the handle lever 8 for adjusting the amount of discharge water and a rotary motion of the handle lever 8 for adjusting the temperature of the discharge water to the movable valve 4. In correspondence to the linear motion and the rotary motion of the handle lever 8, the lever holder 1 slides on a sliding portion between it and the disk actuating stem 2, between it and the movable valve 4, and between it and a housing 3. The sliding portion is important because it affects the operability of the handle lever 8. In the conventional Single lever mixing valve, it is essential to apply a lubricant such as silicone grease to the sliding portion to allow smooth sliding of the handle lever 8 and the other members.
However, in recent years, people are more and more conscious of environmental hygiene. Thus, more and more users are unwilling to use the silicone grease although it is not harmful for the human body.
In the case where the single lever mixing valve is used in a particular environment, for example, a restaurant or the like and in case where it is used at high frequencies, the lubricant may decrease. With the decrease of the lubricant, an operator feels that the handle lever becomes heavy with time in its operation, squeaking sounds are generated during the operation thereof, and the operability thereof will deteriorate.
To apply the lubricant such as the grease to the sliding surface, it is necessary to produce the process of preparing the lubricant, applying the grease to the sliding portion, and maintaining grease-applying device. Consequently, the production efficiency will deteriorate.
The relationship between the handle lever 8 and the disk actuating stem 2 is described below with reference to FIG. 14. The handle lever 8 of the conventional single lever mixing valve is rotated on the disk actuating stem 2 square pillar-shaped or the like to rotate the movable valve 4 accommodated in the housing 3 to thereby adjust the amount of the discharge water, and the angle of the handle lever 8 with respect to a horizontal line is changed to incline the axis of the disk actuating stem 2 to thereby adjust the amount of discharge water by means of the movable valve.
The disk actuating stem 2 is fixed to the fit-in hole 8a formed in the vicinity of an end of the handle lever 8 opposite to the gripping portion thereof with a screw 8b, with the disk actuating stem 2 fitted in the fit-in hole 8a. A blindfolding plate-shaped cap 8c made of synthetic resin is installed on the screw 8b. 
As shown in FIGS. 15 and 16, according to one mode of screwing the disk actuating stem 2 and the handle lever 8 to each other, a screw hole 2b is formed axially in the disk actuating stem 2 from an end surface thereof, and the screw 8b is inserted into a through-hole 8d formed in the vicinity of one end of the handle lever 8. According to another mode of screwing the disk actuating stem 2 and the handle lever 8 to each other, as shown in FIG. 16, the screw 8b is screwed into the screw hole 2b formed horizontally from one end surface of the handle lever 8, and the front end of the screw 8b is pressed against the disk actuating stem 2 to fix the disk actuating stem to the handle lever 8.
However, in any of the above-described conventional single lever mixing valves, the handle lever and the disk actuating stem are fixed to each other with a screw to which a loosening prevention agent (commercial name: Lock-tight) applied to increase the friction resistance of the surface of the screw. Thus, a handle lever-installing operation takes time and labor.
Further, in the handle lever-installing operation, screw-tightening degrees are apt to be nonuniform. Thus, produced single lever mixing valves are liable to have nonuniform tolerances.
Further, during the use of the single lever mixing valve, there is a possibility that the loosening prevention agent penetrates into a sliding portion between mixing valves of the single lever mixing valve little by little. If the loosening prevention agent remains on the sliding portion, the sliding portion is worn. Consequently, a liquid such as water passing through single lever mixing valve is easy to leak.
Furthermore, the action of the loosening prevention agent of preventing loosening of the screw deteriorates gradually with time. Thus, the long-time use of the single lever mixing valve causes the screw to be loose and makes it difficult to operate the handle lever securely.
Consequently, an operator feels that the handle lever becomes heavy with time in its operation, squeaking sounds are generated during the operation thereof, and the operability thereof will deteriorate.
The present invention has been made to overcome the above-described problems. Accordingly, it is an object of the present invention to provide a single lever mixing valve eliminating application of a lubricant to sliding portion in consideration of environmental hygiene, allowing an operator to feel that the handle lever is lightweight in its operation even though the lubricant is not applied to the sliding portion, preventing a torque from fluctuating with time, and allowing the handle lever to be operated easily.
It is another object of the present invention to provide a single lever mixing valve having a simple handle lever-fixing construction eliminating the need for application of a loosening prevention agent. It is still another object of the present invention to provide a single lever mixing valve allowing the handle lever to be operated lightly and securely even though the single lever mixing valve is used for a long time.
More specifically, in the single lever mixing valve, a handle lever-installing operation can be accomplished in a possible simplest degree and assembled without taking much time and labor. It is still another object of the present invention to provide a single lever mixing valve which allows the handle lever to be Installed securely, has a uniform tolerance, prevents the handle lever from being loose or causing no troubles even though the single lever mixing valve is used over as many as 200,000 cycles, and prevents a movable disk and a fixed disk from being damaged easily.
To achieve the object, there is provided a single lever mixing valve comprising a sliding member sliding on a lever holder, and a disk actuating stem supported with the lever holder, for adjusting an amount and temperature of discharge water by inclining or rotating on an axis thereof the disk actuating stem to be operated by a handle lever. One sliding surface of at least one of the sliding portions in which the lever holder and the sliding member slide on each other is formed of a polyamide resinous composition.
The polyamide resinous composition contains polyolefin resin essentially or is aromatic polyamide resin. The aromatic polyamide resin in the present invention has aromatic rings in its chemical structure of polymeric main chain.
One sliding surface or both sliding surfaces of at least one of the sliding portions are formed of the polyamide resinous composition. Thus, the sliding surface has favorable sliding performance, Consequently, the torque of the handle lever hardly fluctuates with time during the operation of the handle lever even though the lubricant is not applied to the sliding portions. Thus, it is possible to provide the greaseless single lever mixing valve.
According to another aspect of the present invention, there is provided a single lever mixing valve for adjusting an amount and temperature of discharge water by rotating a disk actuating stem, on an axis thereof or by operating a handle lever for inclining the axis of the disk actuating stem. A fit-in hole is so formed on the handle lever that the disk actuating stem is loosely fitted therein, with a gap formed between a side surface of the disk actuating stem and a gap-defining inner surface of the handle lever. A spacer so sized as to close the gap is provided. A spacer insertion hole is formed in the handle lever such that the spacer insertion hole is open on an outer surface of the handle lever. The spacer is inserted into the spacer insertion hole to fix the disk actuating stem fitted in the spacer insertion hole.
In the single lever mixing valve, it is possible to adopt the construction in which the spacer insertion hole is formed in penetration through the handle lever in the range from the gap to the outer surface of the handle lever.
In the single lever mixing valve, it is possible to adopt the construction in which the spacer insertion hole is wedge-shaped such that the insertion hole becomes gradually smaller toward an inner end along the gap.
In the single lever mixing valve having the above described construction, the disk actuating stem is loosely fitted in the fit-in hole of the handle lever made of resin, with a gap formed between the side surface of the disk actuating stem and the gap-defining inner surface of the handle lever. Therefore, it is simple and speedy to fit the disk actuating stem in the handle lever. There is no gap left by merely inserting the spacer into the spacer insertion hole on the outer surface of the handle lever. Thus, the disk actuating system can be fixed to the fit-in hole, with both in close contact with each other. This construction eliminates the need for the provision of a screwing construction and for the application of a loosening prevention agent.
Further, a certain fixing force can be obtained owing to the frictional engagement between the fit-in hole and the disk actuating stem. Thus, the single lever mixing valve has a uniform tolerance.
In the above-described construction in which the spacer insertion hole is formed in penetration through the handle lever in the range from the gap to the outer surface of the handle lever, the spacer is pressed against the side surface of the disk actuating stem and allows the disk actuating stem and the handle lever to closely contact each other.
In the above-described construction in which the spacer insertion hole is wedge-shaped such that the insertion hole becomes gradually smaller toward the inner end along the gap, the spacer inserted into the spacer insertion hole expands the narrow portion of the inside of the spacer insertion hole. Consequently, the fit-in hole formed in the handle lever so deforms that the gap decreases. When the fit-in hole has made a deformation to the maximum, the side surface of the fit-in hole and that of the disk actuating stem are pressed against each other.
It is preferable to adopt the construction in which a concave portion or a convex portion which fits in the concave portion is formed on a side surface of the fit-in hole or the disk actuating stem to prevent the disk actuating stem from sliding axially. This construction fixes the handle lever and the disk actuating stem to each other securely.
In the single lever mixing valve having such a construction, the fit-in hole and the disk actuating system are so locked to each other with the convex portion and the concave portion that the disk actuating stem is incapable of moving axially. Thus, the slip-off of the handle lever is securely prevented.
In the single lever mixing valve having any one of the above described constructions, a linear projection is formed on a side surface of the spacer or a side surface of the spacer insertion hole along a spacer insertion direction.
In the construction, when the spacer is inserted into the spacer insertion hole, both members contact each other through the linear projection. That is, both members contact each other not entirely. Thus, both members contact each other in a smaller area when and after the spacer is inserted into the spacer insertion hole. Therefore, the friction resistance is low, which allows a smooth operation of inserting the spacer into the spacer insertion hole and removing it therefrom to replace component parts.